SU785977A1 - Device for discriminating synchro pulses - Google Patents

Description

one

The invention relates to a pulse technique and can be used to start a horizontal scan generator of an oscilloscope CRT.

A device containing 5 oscilloscope, microprocessor, digital-to-analog converter and two comparators is known, which generates a start pulse, a delayed sweep generator of a CRT beam at the time of comparison at the inputs of the main sweep comparator and a voltage level proportional to the delay time selected by the operator (1 ..15

A disadvantage of the known device is that the search, extraction and movement of the pulses of the monitored sequence, 20 different from the norm, are performed only on the portion of the monitored sequence of signals shown on the screen of a CRT.

Of the known devices, the most 25 closest in technical essence is a device containing a code dial switch, an oscilloscope, a clock generator, a counter, a control unit, and a monitoring analyzer.

sequence of C2 signals.

However, the lack of a constructive connection from the output of the video signal analysis unit to the input of the oscilloscope sweep timing control unit reduces the device performance and limits the operation of the device, for example, when detecting distorted monitored signals.

The purpose of the invention is to expand the functionality of the device.

This is achieved in that a device containing a code dial switch, an oscilloscope, serially connected clock generator and a counter, serially connected control unit and analyzer of a monitored signal sequence, the output of which is connected to the input of the control unit, serially connected switchboard, trigger register and comparison unit, the output of which is connected to the input of the oscilloscope, while the first input of the switch is connected to the output of the switch of the dialing code, and the second and third I a key switch rows nor to the second and third output control unit.

FIG. 1 is a functional diagram of the device for the selection of synchronization pulsesJ in FIG. 2 voltage plots that illustrate the principle of operation of the device.

A device for impulse synchronization (see Fig. 1) contains an oscilloscope 1, a clock generator 2, a counter 3, a parity check block 4, a switch 5, a switch b, a trigger register 7, a compare block 8. Control block 9, outputs 10, 11 and 1 of which are connected to the control inputs of the control unit 4 and the switch 6 of the two input channels.

In order to demonstrate the operation of the sync pulse extraction devices, a controlled product is connected to it, for example, a permanent storage device (ROM) 13. ROM inputs are connected to the outputs of counter 3, ROM outputs 14 are connected to the control unit 4, and ROM outputs 15 are connected to the vertical amplifier input oscilloscope deflection 1. Clock pulses U 1 (see Fig. 1) from the output of generator 2 are fed to a counter, which when connected to a ROM, acts as a generator of address codes for a PZ. Each address code at the output of a counter 3 corresponds to some This information is on output 14 of the ROM, satisfying the parity law. Each combination of address signals at the inputs of the ROM includes a certain group of memory elements, decoders, keys, and bit amplifiers of the ROM. Busting all combinations of address codes on the counter 3 allows you to connect all the elements of the ROM in turn. The control over the operation of the constituent elements of the ROM is performed at the outputs 15 of the ROM. A deviation from the parity of the information of the outputs 14 of the ROM is a signal of the unstable operation of some elements of the ROM. According to the parity error signal, the circuit of the proposed device stores the number of the clock in which the parity mismatch is registered and then when accessing the ROM in the cyclic memory search mode, the CRT beam sweep generator starts at the times corresponding to the indicated clock time. Running the sweep generator on the basis of a parity error allows you to output pulses from the outputs of the ROM elements operating in a given clock cycle in which the parity failure occurs at the beginning of the sweep, therefore, it is possible to monitor the operation of the elements that cause the ROM to fail. With this control, when the start of the sweep of the beam and the parity failure coincide in time, auto

Mathematical search and selection of pulses from the controlled sequence.

A device for extracting synchronization pulses operates as follows.

In case of a parity error in the codes read from the ROM, the control unit 4 generates a signal U2 (see Fig. 2), which is transmitted to the input of the control unit 9. The response of the control unit 9 is that at its output 11 a high voltage level U 3 (Fig. 2) is set to the time of action of the signal U2, to enable the transmission of the counter code 3 (for example, a code from three bits of the counter and 4, and 5, B) to register 7 (for example, three bits of the register 1/7, U8, and 9), and at the end of the clock cycle at output 10 a low voltage level (UIO) is set to block the operation of the control unit. In the following device operation cycles, the address codes are changed at the counter outputs and the counter codes are compared with the register code in the comparison block, if the output of the comparison block 8 is equal, a pulse U11 is formed at the beginning of the clock (see Fig. 2), which is used for triggering synchronization horizontal beam generator CRT.

If there are several errors in the monitored process, the operation of the device is similar to that described above, however, the device uses an additional interrupt unit (not shown), which is installed in the open circuit from the output of control unit 4 to the control unit. The additional block contains a reset button, a keyboard register, a counter, a comparison circuit, trigger RS.

The operation of the additional unit is terminated as follows. On the key register set the error number, then from the button reset the trigger RS to zero. The signals from the output of control unit 4 change the state of the counter even with a code equal to the code at. key register, the output of the comparison circuit produces a pulse of setting the RS trigger into one, a signal from the output of the RS trigger arrives at the input of the control unit 9, and the counter 3 code is overwritten into the register 7. The next synchronization pulse of the sweep will be selected to coincide with elements of the ROM, generating the N-th error. The output pulses from these elements through the outputs 15 of the ROM are fed to the input of the amplifier for the vertical deflection of a CRT beam. This creates favorable conditions for detailed analysis and accurate measurements.

images of slit pulses on a CRT screen.

When the device operates from a switch (or from a computer connected instead of a switch) at the outputs 10 and 11 of the control unit, a low voltage level U 10 and and 4 is set (see Fig. 2) prohibiting the transmission of information to the control unit and to the first inputs of the switch and at the output 12 of the control unit 9 the potential of the high level U 12 is set, the code from the switch 5 (or from the computer) is transmitted to the register 7, the information from the output of the register L / 7, U 8, V9 is compared with the current address codes of the counter 3 , with equal codes of counter 3 and register 7, the output pulse of the beam sweep generator is generated at the output of the comparator unit 8, while at the beginning of the beam sweep some pulse is placed from the output 15 of the ROM, and the choice of the pulse from the sequence of monitored signals is performed by software.

Distinctive features of the device for the selection of synchronization pulses expand the functional capabilities of the device, ensure the synchronization of the start of the CRT beam sweep under the conditions of the software control of the device and the results of the analysis of failures and errors in the monitored product. Expanding the functionality of the device improves the performance of devices using the invention (for example, diagnostic stands and computer units, oscilloscopes), increases the operator's productivity in debugging newly developed products, reduces the development time of new products and complexes, and adjusts the production of serial products.

Claims (2)

Invention Formula A device for extracting synchronization pulses, comprising a code dialing switch, an oscilloscope, serially connected clock generator and counter, serially connected control unit and analyzer of monitored sequence of signals, the output of which is connected to the input of the control unit, characterized in that devices injected in series 0 k 4 switch, trigger register and comparison unit, the output of which is connected to the oscilloscope input, the first input of the switch connected to the output of the switch of the set of codes, and the second and third inputs of the switch connected to the second and third outputs of the control unit. Sources of information taken into account in the examination 0 1, Lo, Tagioff, The use of two delayed sweeps is a cheaper and simpler method for measuring temporal relationships, Electronics, 1977 (3, p. 54 .. five 2. Oscilloscope With 1-57. Technical description and operating instructions AND 22.044.041 THAT, 1975, p. 22-25. LrL ... n L U6 U9. ju un Uf2 fug. 2 ... j